Taming the beasts… aka suricata blueprint
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Yeah, I think we speak different languages.
I am not talking about WAN interface, not sure why you brought it in.
I am talking about Snort/Suricata instance on LAN interface. In case of non-transparent proxy it does not see external IPs, period.
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WAN is brought in because it is needed to connected to the outside world. If you have the same rules on both interfaces and an alert pops up; the WAN interface will block the the external IP. interface. Since you should have the same alert for both interfaces, you can cross reference the WAN/LAN alert logs to find the internal IP on your LAN interface. I get what you're saying now about the LAN not blocking the the internal IP since its already white-listed. I haven't had any LAN clients stumble any malicious javascript yet.
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Yeah, I think we speak different languages.
I am not talking about WAN interface, not sure why you brought it in.
I am talking about Snort/Suricata instance on LAN interface. In case of non-transparent proxy it does not see external IPs, period.
snort/suricata interface on LAN should show the same alert that snort/suricata on the WAN will show. If you did change the pass list, then both the internal (private) IP and the external (malicious site) IP will be blocked. If you still think that pfsense will not see the internal IP because it somehow "travels through the proxy" then you are missing a critical piece of information. snort/suricata are running the interfaces as promiscuous. That means they see every single packet that hits them, even if it's not destined for them. snort/suricata will see the packets from the laptop to the proxy (assuming proxy on pfsense), the proxy's answer to the laptop (both on LAN interface) and the request from the proxy to the malicious site, and the malicious site answer to the proxy (WAN interface). Anything that flags an alert with any of that will result in an IP being blocked, even internal IPs. Period. (throwing it in there, since something clicks in my head when someone says period to me, then everything turns black).
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If you have the same rules on both interfaces and an alert pops up; the WAN interface will block the the external IP. interface. Since you should have the same alert for both interfaces, you can cross reference the WAN/LAN alert logs to find the internal IP on your LAN interface. I get what you're saying now about the LAN not blocking the the internal IP since its already white-listed. I haven't had any LAN clients stumble any malicious javascript yet.
Yes, that is the point I am trying to make - in such case you have to have appropriate rules enabled on WAN interface and, as you said, there is a need to find which internal IP it was, on the LAN interface as well… But that is a lot of manual labor to cross-reference alert logs :( And the additional memory used for duplicate rules...
For me, Snort http preprocessor with its built-in inspection rules (like (http_inspect) HTTP RESPONSE HAS UTF CHARSET WHICH FAILED TO NORMALIZE) is too noisy and blocks normal sites often.
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@jflsakfja:
Anything that flags an alert with any of that will result in an IP being blocked, even internal IPs.
Don't know about you, but in my setup internal IPs are in the safe list by default (did I repeat it 3rd time?).
Oh, and I am not complaining about that. -
@jflsakfja:
Anything that flags an alert with any of that will result in an IP being blocked, even internal IPs.
Don't know about you, but in my setup internal IPs are in the safe list by default (did I repeat it 3rd time?).
Oh, and I am not complaining about that.I also repeated 3 times that you can actually change the PASS list so they are not.
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And why would I need to remove my internal network from the pass list?
What is the use case? May be for some public hotspot it may make sense, but not for the trusted network… -
There is no such thing as a trusted network. As I said somewhere else, the only thing you should trust is the little voice inside your head. Everything/everyone out there is out to get you. And no, it's not paranoia when they ARE out to get you.
NSA aside, the use case is when trying to limit a local (internal) host from spreading something nasty on the internet. Other than that, there is no use for it, since it can still spread the "nasty" to other hosts on its subnet. When each host is on a different subnet, that's a different story, it effectively blocks it from accessing the entire network, but that is a highly specialized use case (ie not something you will encounter outside of an ISP).
Another use case that pops into my mind is when providing internet access to others (free wifi anyone?). You can't tell what their systems are infected with, so to limit your liability you could block it from accessing the internet.
As you can see from the guide, most weight is put into securing the network from outside threats, with some weight given on somewhat limiting outgoing connections. My recommendation for a normal home network is to use your trusted network example. Perfectly normal paranoia aside, it's very unlikely the NSA has broken into your house/computer-while-it-was-shipped and installed a backdoor. Incoming "nasties" are blocked. Since they are blocked, and you use some common sense (a shocking truth, but that hottie that keeps sending you naked images of her, is actually trying to get your email client to parse a command obfuscated in the image, ala firefox (yes a browser) jpg code execution), your network is (mostly) safe. Yes there are other attack vectors (eg browser memory mismanagement) but those are outside the scope of this guide :D.
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Here is a report from The Solutionary Security Engineering Research Team (SERT) Quarterly Threat Intelligence Report for Q2 2014
http://www.solutionary.com/research/threat-reports/quarterly-threat-reports/sert-threat-intelligence-q2-2014/
Key findings include:
The top 10 ISPs represented the source of 52% of the malware identified in the new period.Amazon-hosted malware nearly triples in first half of 2014.
56% of malware captured was hosted in the United States, a 12% increase from Q4’13
Malicious SSH activity continues to be a popular method to gain administrative access to target systems.
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Not going to register to download a report that I'm responsible of producing at my work :p
Let me guess, they propagate the Chinese 1337 hackers meme?
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@jflsakfja:
Not going to register to download a report that I'm responsible of producing at my work :p
Let me guess, they propagate the Chinese 1337 hackers meme?Its great that you are cataloging these Malicious Attempts in your network. But its important to have a well balanced Source of Threats. Some Sources are good for Mail Servers, others Malware, others SSH attack etc. By combing threat sources from a multitude of Threat Sources, you can better determine their IP Reputation.
I typically don't like to have to register for Reports also. But looking at the Solutionary Website, there are other reports available online without needing to register.
http://www.solutionary.com/research/threat-reports/monthly-threat-reports/2014/06/security-threat-report-june-2014/
Looking at my current suggested List of Blocklist Sources (See data below),
grep "98.124.198.1" pf/*
pf/ET_IPrep.txt:98.124.198.1
pf/e_tcnc:98.124.198.1
pf/e_tdrop:98.124.198.1grep "85.159.211.119" pf/*
pf/ET_IPrep.txt:85.159.211.119
pf/e_tblackhole:85.159.211.119
pf/e_tcnc:85.159.211.119grep "85.25.148.6" pf/*
pf/IBlock_BT_Spy.txt:85.25.148.6
grep "217.12.207.151" pf/*
pf/IBlock_BT_Spy.txt:217.12.207.151
grep "192.99.6.61" pf/*
no results
grep "192.99.6.0" pf/*
no results
grep "^192.99." pf/*
pf/ToastedSpam.txt:192.99.0.0/16Game Over Zeus Botnet (goz)
http://garwarner.blogspot.ca/2014/07/new-gameover-zeus-variant-uses-fastflux.html?m=1Only ET IQRisk Blocklist picks up all of these IPs.
I have seen this spam hit my Network "E-ZPass" (I forwarded them to SpamCop also)
http://garwarner.blogspot.ca/2014/07/e-zpass-spam-leads-to-location-aware.html?m=1Only ET IQRisk Blocklist picks up all of these IPs.
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Right, I finally have a little bit more time to work on this now :P
Could I ask one more question, JFL?
This is what I am struggling with:
1. You said in one thread (I think it was your previous thread about how to set up Snort) said to ditch Snort for Suricata;
2. Some Snort rules (some 600 I believe Bill said) Suricata can not interpret.
3. Your current instructions (this thread) only deal with the ET-rules, not with the Snort rules.
4. I take it ET doesn't completely overlap the Snort (paid subscription, which is what I have) rules, so there is/might be value in using both the Suricata- and Snort rules in Suricata.What would be wisdom here? Take your old instructions about the Snort rules to know what to disable, or do you consider these instructions obsolete perhaps? If so, ditch Snort all together? (but then point 4?) If not ditch Snort, how do you cope with the rules Suricata can't handle (the Snort rules)? There are 600 it seems, so [a1] how to find out which ones and [a2] after disabling these, aren't we missing out on important protection?
Or: have both Snort and Suricata inspect the interfaces at the same time (Snort with the full subscriber rule set, Suricata with the ET rule set)?
Yes, vague and complex for a stupid economist like me, I know :-[
( ;D )
Thank you again very much :P
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@Hollander:
1)The only reason suricata is better than snort is that snort's inline has been abandoned and the developers moved to suricata, so if you want an IPS then you have to use suricata. We are talking about the general majority of users out there, there are other differences, but most users will never notice them. There is NO other software out there that matches its capabilities right now, pay,free,donated-to-us-by-aliens. It is actually the top of the line, absolute best IDS/IPS available. It bloody hell should be the best, it was funded directly by the U.S. government, I'm sure those guys want to get their money's worth.2)As far as the rules that suricata cannot interpret you only have these 2 choices:a)don't use them or b)manually rewrite the rule so that it is accepted by suricata.
3)This thread is about suricata, so there is no point in dealing with the snort rules, since those rules are not used. My opinion as to whether they are updated, or not, is my opinion only and does not reflect the opinion of The Company, etc… etc...
4)If you followed the guide to the letter and actually set up your suricata as suggested, you should be seeing about 90% banned hosts from custom rules (simple port scanning rules that detect port scans even the ET rules miss). Do you want to focus on the 1% that is banned hosts from the snort rules (assuming you are using snort with suricata, and filtered out the not working rules), the 9% from ET rules, or the 90% from custom rules? ;)
The trick to setting up an IDS/IPS is thinking like an attacker. What would you do to compromise an unknown system? These are the steps (most) attackers worth their salt follow (note: Does NOT refer to Chinese and Korean so called "state sponsored hackers", I don't have the time to deal with script kiddies):
a) Identify who the system belongs to. If it belongs to a letter soup agency, have the drill ready (you do have a "In the case of emergency, drill HERE" sticker that when followed shatters the HDD's platters right? Easy access to RAM modules (cold attack) is a bonus.
b) Identify used services. Usually a full portscan follows that identifies the used ports. This is the first trap we set up. Following this guide, ALL privileged ports are now under constant check. A portscan (even so called "sophisticated" portscans, using actual TCP handshakes (not trying to trick the system into responding)) WILL hit our trap if it's destined for privileged ports (probability it is:infinite).
c) In the case of true "state sponsored hackers" I personally expect them NOT to perform portscans. They should have been at one of my classes so far (if you are a state sponsored hacker and have missed my training classes, please contact your supervisor for a re-schedule) and should have known by now than when attacking, you NEVER alert the victim. And yes, I am talking to you United States Army Information Systems Control (now integrated into NETCOM). How many times have you seen a cat running around screaming "ARE THERE ANY MICE HERE??????" It crawls silently next to its victim, then attacks. The same strategy should be implemented here: Perform a legitimate connection to a used port, and see what information you can gather from it. If it spews out that the webserver used is a known buggy version, then find the exploit for it and attack it. It's not rocket science. This is were security by obscurity comes in handy. If you don't allow the attacker to understand the version of a software used, then the attacker is more likely to screw up by trying to use known large scale exploitable bugs (bugs that should be corrected by your updates long ago. You are updating without delays right?). Suricata will fire up an alert on old exploits, since I will not bother with the latest and greatest exploits. If my upstream distribution patches the flaw within 8 hours of it being public, and ET publishes a rule update at the end of the day, I'll take my upstream distribution over ET any time. What I'm trying to say here is, there is no point in trying to keep up with exploits using rules, you should instead keep up with exploits using server admin best practices. 99.999% of so called "industry leaders" have absolutely NO idea when the last time their servers were updated. I've seen SSL certificates being expired for a WHOLE YEAR being used by a so called "leading web hosting provider", and I believe my, and everybody's, conclusion is that if you did not see that your SSL certificate has been expired for the past year, there is at least a 1 year gap between the last time you checked and updated the server and now. 1 year of NOT patching a system is the difference between a compromise and not.
d) The attacker has successfully exploited a known flaw and is now on your system. This is were inward facing interfaces come in handy. If a webserver starts scanning your firewall for open ports, then this is a clear sign of a compromised system. If that same webserver starts sending out reflection attacks out of nowhere, it too is a clear sign of a compromise. Ideally in this case the IDS/IPS will block the server. Having a few angry customers is better if you handle your compromise transparently. An announcement somewhere along the lines of "We have detected signs of a system compromise and have to shut down a system pending further investigation" will go a long way instead of, I don't know, SITTING ON A COMPROMISE FOR 2 MONTHS? coughebaycough pardon my Vogons. Seeing your webserver ending up on your IDS/IPS's banned hosts list is your hint to pick up the phone, give me a call and say "hello, are you offering forensic analysis services? Yes, we have had a system compromise. Ok I'll see you on monday". You should never ask how much a forensic analysis of a compromised host costs. It's a case of a "if you have to ask how much it costs, you cannot afford it".Summary because I just previewed the post and my $deity I write long posts :p.
Use the IDS/IPS to detect and prevent network attacks. Use server best practices to STOP host attacks. If you are using snort/suricata for a home network, most of these points are invalid, since the only way in is:
1)browser bug
2)email client bug
3)irc/messenger/voip client bug
4)"any service that performs connections with a remote network" bugTrust me, if I can't see it, I can't shoot at it. Light bending around planets to look behind them (not the keep a google tab open type, if I can't type its name out of my head, I don't bother) does not apply in network/system security.
Ideally the bugs should be handled by your upstream (commercial company,beer drunk open source developers, depends on the case) swiftly and your exposure will be minimized. This is where common sense comes in. I will never delay updating a critical software to a newer version that fixes a bug because I don't like the newer version's interface. A little hint here: based on my professional experience, updating a system first, THEN checking what/if-something doesn't work is the best way to maintain a system. This also depends on the distro you are using. If you are using distro X because "ZOMGWTFBBL it uses the latest version of text editor nobody uses!!!ZOMGWTFLOLBEES" then ditch it and start using distros created before the other distro's creators were even born. In other words, if you are using a debian derivative, STOP as soon as possible (yesterday would be nice) and start using debian. Use the money you saved from unscheduled downtimes, things breaking right and left, and support financially debian. If I was a developer and was starving to death, I wouldn't sit down and code the bug fix for you. If you offered me a piece of pizza, then sure as hell I would sit down. I would even fix that other bug that is affecting you but isn't so serious. -
Only ET IQRisk Blocklist picks up all of these IPs.
Would be great to be able to get access to this at a Snort consumer licence or similar price. I asked a few months back and was told ET got rid of it due to abuse by enterprise customers abusing the offer.
One thing that would be a reassuring addition for the dashboard widget would be a date/timestamp when the rules were last updated.
I'm very impressed with Suricata and this threads guidance, thank you.
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@irj972:
Only ET IQRisk Blocklist picks up all of these IPs.
Would be great to be able to get access to this at a Snort consumer licence or similar price. I asked a few months back and was told ET got rid of it due to abuse by enterprise customers abusing the offer.
Would be good if they change their minds. More People need to speak up and ask them for a better package.
One thing that would be a reassuring addition for the dashboard widget would be a date/timestamp when the rules were last updated.
This is already part of my latest widget.
https://forum.pfsense.org/index.php?topic=78062.msg432181#msg432181
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@Hollander:
This is what I am struggling with:
1. You said in one thread (I think it was your previous thread about how to set up Snort) said to ditch Snort for Suricata;
2. Some Snort rules (some 600 I believe Bill said) Suricata can not interpret.
3. Your current instructions (this thread) only deal with the ET-rules, not with the Snort rules.
4. I take it ET doesn't completely overlap the Snort (paid subscription, which is what I have) rules, so there is/might be value in using both the Suricata- and Snort rules in Suricata.Suricata will not load the Snort Shared Object Rules. You can disable all of the Snort SO Categories for each Interface in the Categories Tab, or just leave it as is, and Suricata will just skip the Snort SO Categories. It will still load the remainder of the Snort Categories. You can refer to the previous Snort Recommended Disable List, or just disable as you see false positives.
What you don't want to do is run both Snort and Suricata in Blocking Mode at the same time which will cause issues. If you want to run both, only one can be in Blocking Mode.
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@jflsakfja:
@Hollander:
1)The only reason suricata is better than snort is that snort's inline has been abandoned and the developersA joy to read once again, JFL ;D
Armed with this knowledge, and the reply from BB right above about which Snort rules to disable (thanks again BB :P ) I reserved two hours to start disabling and enabling. Unfortunately, it seems Bill still didn't have time to make the enabling all and then disabling some-routine slightly more comfortable. He announced he will do that, so I will have to wait for that. Because the current way of working will require me to weeks of from work :-X
(1. Enable all -> 2. start to disable the exceptions -> 2a. disable first exception, it will not be disabled but will have the bright red cross -> wait for pfSense to process and respond back -> 2b. click the same cross once again & wait for pfSense to respond after which it will have the desired light yellow cross. That is not doable in a few hours with all the many rules I will have to manually disable).
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I didnt know Suricata offered inline detection and blocking in Pfsense?
For what I know it works more or less the same way as Snort does (not inline)
Enlighten me pls :)
@jflsakfja:
@Hollander:
1)The only reason suricata is better than snort is that snort's inline has been abandoned and the developers moved to suricata, so if you want an IPS then you have to use suricata. We are talking about the general majority of users out there, there are other differences, but most users will never notice them. There is NO other software out there that matches its capabilities right now, pay,free,donated-to-us-by-aliens. It is actually the top of the line, absolute best IDS/IPS available. It bloody hell should be the best, it was funded directly by the U.S. government, I'm sure those guys want to get their money's worth.2)As far as the rules that suricata cannot interpret you only have these 2 choices:a)don't use them or b)manually rewrite the rule so that it is accepted by suricata.
3)This thread is about suricata, so there is no point in dealing with the snort rules, since those rules are not used. My opinion as to whether they are updated, or not, is my opinion only and does not reflect the opinion of The Company, etc… etc...
4)If you followed the guide to the letter and actually set up your suricata as suggested, you should be seeing about 90% banned hosts from custom rules (simple port scanning rules that detect port scans even the ET rules miss). Do you want to focus on the 1% that is banned hosts from the snort rules (assuming you are using snort with suricata, and filtered out the not working rules), the 9% from ET rules, or the 90% from custom rules? ;)
The trick to setting up an IDS/IPS is thinking like an attacker. What would you do to compromise an unknown system? These are the steps (most) attackers worth their salt follow (note: Does NOT refer to Chinese and Korean so called "state sponsored hackers", I don't have the time to deal with script kiddies):
a) Identify who the system belongs to. If it belongs to a letter soup agency, have the drill ready (you do have a "In the case of emergency, drill HERE" sticker that when followed shatters the HDD's platters right? Easy access to RAM modules (cold attack) is a bonus.
b) Identify used services. Usually a full portscan follows that identifies the used ports. This is the first trap we set up. Following this guide, ALL privileged ports are now under constant check. A portscan (even so called "sophisticated" portscans, using actual TCP handshakes (not trying to trick the system into responding)) WILL hit our trap if it's destined for privileged ports (probability it is:infinite).
c) In the case of true "state sponsored hackers" I personally expect them NOT to perform portscans. They should have been at one of my classes so far (if you are a state sponsored hacker and have missed my training classes, please contact your supervisor for a re-schedule) and should have known by now than when attacking, you NEVER alert the victim. And yes, I am talking to you United States Army Information Systems Control (now integrated into NETCOM). How many times have you seen a cat running around screaming "ARE THERE ANY MICE HERE??????" It crawls silently next to its victim, then attacks. The same strategy should be implemented here: Perform a legitimate connection to a used port, and see what information you can gather from it. If it spews out that the webserver used is a known buggy version, then find the exploit for it and attack it. It's not rocket science. This is were security by obscurity comes in handy. If you don't allow the attacker to understand the version of a software used, then the attacker is more likely to screw up by trying to use known large scale exploitable bugs (bugs that should be corrected by your updates long ago. You are updating without delays right?). Suricata will fire up an alert on old exploits, since I will not bother with the latest and greatest exploits. If my upstream distribution patches the flaw within 8 hours of it being public, and ET publishes a rule update at the end of the day, I'll take my upstream distribution over ET any time. What I'm trying to say here is, there is no point in trying to keep up with exploits using rules, you should instead keep up with exploits using server admin best practices. 99.999% of so called "industry leaders" have absolutely NO idea when the last time their servers were updated. I've seen SSL certificates being expired for a WHOLE YEAR being used by a so called "leading web hosting provider", and I believe my, and everybody's, conclusion is that if you did not see that your SSL certificate has been expired for the past year, there is at least a 1 year gap between the last time you checked and updated the server and now. 1 year of NOT patching a system is the difference between a compromise and not.
d) The attacker has successfully exploited a known flaw and is now on your system. This is were inward facing interfaces come in handy. If a webserver starts scanning your firewall for open ports, then this is a clear sign of a compromised system. If that same webserver starts sending out reflection attacks out of nowhere, it too is a clear sign of a compromise. Ideally in this case the IDS/IPS will block the server. Having a few angry customers is better if you handle your compromise transparently. An announcement somewhere along the lines of "We have detected signs of a system compromise and have to shut down a system pending further investigation" will go a long way instead of, I don't know, SITTING ON A COMPROMISE FOR 2 MONTHS? coughebaycough pardon my Vogons. Seeing your webserver ending up on your IDS/IPS's banned hosts list is your hint to pick up the phone, give me a call and say "hello, are you offering forensic analysis services? Yes, we have had a system compromise. Ok I'll see you on monday". You should never ask how much a forensic analysis of a compromised host costs. It's a case of a "if you have to ask how much it costs, you cannot afford it".Summary because I just previewed the post and my $deity I write long posts :p.
Use the IDS/IPS to detect and prevent network attacks. Use server best practices to STOP host attacks. If you are using snort/suricata for a home network, most of these points are invalid, since the only way in is:
1)browser bug
2)email client bug
3)irc/messenger/voip client bug
4)"any service that performs connections with a remote network" bugTrust me, if I can't see it, I can't shoot at it. Light bending around planets to look behind them (not the keep a google tab open type, if I can't type its name out of my head, I don't bother) does not apply in network/system security.
Ideally the bugs should be handled by your upstream (commercial company,beer drunk open source developers, depends on the case) swiftly and your exposure will be minimized. This is where common sense comes in. I will never delay updating a critical software to a newer version that fixes a bug because I don't like the newer version's interface. A little hint here: based on my professional experience, updating a system first, THEN checking what/if-something doesn't work is the best way to maintain a system. This also depends on the distro you are using. If you are using distro X because "ZOMGWTFBBL it uses the latest version of text editor nobody uses!!!ZOMGWTFLOLBEES" then ditch it and start using distros created before the other distro's creators were even born. In other words, if you are using a debian derivative, STOP as soon as possible (yesterday would be nice) and start using debian. Use the money you saved from unscheduled downtimes, things breaking right and left, and support financially debian. If I was a developer and was starving to death, I wouldn't sit down and code the bug fix for you. If you offered me a piece of pizza, then sure as hell I would sit down. I would even fix that other bug that is affecting you but isn't so serious. -
I didnt know Suricata offered inline detection and blocking in Pfsense?
For what I know it works more or less the same way as Snort does (not inline)
Enlighten me pls :)
Why do I have to always write like I'm presenting a case to the court? Seems like even a miss-placed comma gets the author burned on the stake in these forums.
I have mentioned in the past that snort inline has been abandoned. Says so on their page if you don't believe me.
As it stands right now, the exact moment of this post, yes suricata and snort more or less run the same way on pfsense. BUT: The inline capability is there, it just cannot be used yet as pfsense needs some changes to it. They are coming soon(ish). Would you want to tear down your snort system when the changes are made, reconfigure and troubleshoot suricata, then enable it and forget it, or just log in and tick a checkbox and be done with it?
I don't see why we need to split the development effort between snort and suricata. Snort doesn't offer anything more than suricata, but offers plenty less than suricata. A couple years time down the road, the cisco announcement that snort will no longer be maintained as a community project should wake up everybody. And yes, the announcement WILL come. The same way the ebay announcement came when I was running around screaming "change your ebay passwords!!!" and everybody was looking at me puzzled.
It's unfortunate that an open source project died (snort) but it's survival of the fittest. Now if we could only convince the (about) 43298 different open source text editors to die and merge in a single project, we will be colonizing Alpha Centauri by this time next year, and permission is hereby granted to quote me on that.
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It's unfortunate that an open source project died (snort) but it's survival of the fittest. Now if we could only convince the (about) 43298 different open source text editors to die and merge in a single project, we will be colonizing Alpha Centauri by this time next year, and permission is hereby granted to quote me on that.Ha! Thats good stuff! ;D
